Got the first scratch on my 3GS
Its about 6 inches long, luckily its under the silver trim.. Any tips for touchup?

 

I can't quite figure out the location of your 6" scratch. Where is the "silver trim" located? At any rate, have your tried any of the commercially available scratch removing compounds? When I noticed that my wife's `04 GX470 had a light, 4"-5" scratch on the left rear door, I used a scratch removing compound that I had in the garage and the scratch was gone in seconds. The colour of your GS may make a difference; removing scratches from darker coloured cars may be more problematic.

 

Its the silver trim on the lower door sils (right hand side / rear door).. Ive got a mercury metalic GS. I dont think the scratch removing compund will be of use as the scratch is slightly deep, the paint has gone off..

 

Sorry to read that. If the scratch is fairly deep and has taken off the paint, a touch-up job will only make it worse. You've got to take it to a paint shop. It will probably cost you around $100. Once it's cleaned-up, you may want to consider having someone install a "clear" plastic film to protect it.